TMS320F280049C: Driverlib I2C MPU6050 Help

Hi everyone,

I am working on a project in which I need to poll an accelerometer for motion data, however, I am running into trouble when I try to adapt the example code provided in the DriverLib documentation to my problem. When I hooked up my development board to an oscilliscope, I notice the following behaviour:

C2000: Writes address of MPU to I2C Bus

MPU: No ACK

The code below is trying to request and read back a single register address of the MPU-6050. I have attached the documentation pdf below if you would like to review it. The protocol in question is on page 34.

#include "driverlib.h"
#include <device.h>
#include <stdint.h>

#define WHO_AM_I        0x75
#define MPU_ADDRESS     0x68

void initI2C();
__interrupt void i2cFIFOISR();

uint16_t mpu_data;
uint16_t status;

void main() {
	/* Setup C2000 */
	Device_init();
	Device_initGPIO();

    /* Setup GPIO for I2C */
    GPIO_setPinConfig(GPIO_35_SDAA);
    GPIO_setPadConfig(35U, GPIO_PIN_TYPE_PULLUP);
    GPIO_setQualificationMode(35U, GPIO_QUAL_ASYNC);
    GPIO_setPinConfig(GPIO_37_SCLA);
    GPIO_setPadConfig(37U, GPIO_PIN_TYPE_PULLUP);
    GPIO_setQualificationMode(37U, GPIO_QUAL_ASYNC); 

    /* Setup interrupts */
	Interrupt_initModule();
	Interrupt_initVectorTable();
    Interrupt_register(INT_I2CA, &i2cFIFOISR);

    /* Call i2c setup function */
	initI2C();

    /* Enable interrupts system-wide */
    Interrupt_enable(INT_I2CA);
    EINT;
    ERTM;

    I2C_setDataCount(I2CA_BASE, 1);


    while (1) {
        while (I2C_isBusBusy(I2CA_BASE)) {}
        // I2C_putData(I2CA_BASE, WHO_AM_I);
        I2C_setConfig(I2CA_BASE, I2C_MASTER_SEND_MODE);
        I2C_sendStartCondition(I2CA_BASE);
        status = I2C_getStatus(I2CA_BASE);
    }
}

void initI2C() {
	I2C_disableModule(I2CA_BASE);

    /* Configure for 400 kHz clock with a 50% duty cycle */
    I2C_initMaster(I2CA_BASE, DEVICE_SYSCLK_FREQ, 100000, I2C_DUTYCYCLE_33);
    I2C_setBitCount(I2CA_BASE, I2C_BITCOUNT_8);
    I2C_setSlaveAddress(I2CA_BASE, MPU_ADDRESS);
    I2C_setEmulationMode(I2CA_BASE, I2C_EMULATION_FREE_RUN);

    I2C_enableInterrupt(I2CA_BASE, I2C_INT_REG_ACCESS_RDY | I2C_INT_STOP_CONDITION);

    I2C_enableFIFO(I2CA_BASE);
    I2C_clearInterruptStatus(I2CA_BASE, I2C_INT_RXFF | I2C_INT_TXFF);

    I2C_enableModule(I2CA_BASE);
}

__interrupt void i2cFIFOISR() {
    I2C_InterruptSource source;

    source = I2C_getInterruptSource(I2CA_BASE);


    switch (source) {
        case I2C_INTSRC_REG_ACCESS_RDY:

            if((I2C_getStatus(I2CA_BASE) & I2C_STS_NO_ACK) != 0) {
                I2C_sendStopCondition(I2CA_BASE);
                I2C_clearStatus(I2CA_BASE, I2C_STS_NO_ACK);
            }
            
            I2C_setConfig(I2CA_BASE, I2C_MASTER_RECEIVE_MODE);
            I2C_putData(I2CA_BASE, WHO_AM_I);
            I2C_sendStartCondition(I2CA_BASE);
            mpu_data = I2C_getData(I2CA_BASE);
            I2C_sendStopCondition(I2CA_BASE);
            I2C_setConfig(I2CA_BASE, I2C_MASTER_SEND_MODE);
            break;

        case I2C_INTSRC_STOP_CONDITION:
            I2C_sendStopCondition(I2CA_BASE);
            mpu_data = I2C_getData(I2CA_BASE);
            break;

        default:
            mpu_data = I2C_getData(I2CA_BASE);
            I2C_sendNACK(I2CA_BASE);
            break;
    }


    Interrupt_clearACKGroup(INTERRUPT_ACK_GROUP8);
}

Many thanks!MPU-6050_DataSheet_V3 4.pdf